Hot solenoid

[skcyclist]

I solved the house battery not charging problem. There was blown 60 amp fuse in the Ford fuse box under the hood that supplied the aux. battery. While trouble shooting I found a solenoid just above the main electrical box that gets almost too hot to touch when the main switch is on. The main switch must be on to power camper 12V accessories. Also must be on to charge the battery when the vehicle motor is running. Some research suggests hot continuous service solenoids are normal to keep contacts closed (or open?) while they draw 12 watts of power. Somehow this seems like an unnecessary drain on the battery. Anyone know anything about this? e mail me skc@cox.net Steve

Just looked at some alternative wiring set ups. One showed a solenoid that would go on and off with the ignition. That makes a lot more sense than having it on all the time. But maybe I'm overlooking something.

[markopolo]

Typical camper vans will have an Isolator or Separator that keeps the chassis and house battery separate but allows both to be charged by the vehicles alternator.

Additionally, there is the house 12v system disconnect which is what I think you are referring to.

Intellitec battery disconnects require no power to stay open or closed. So maybe an upgrade is needed.
http://intellitec.com/pdfs/BATTERY_web/bd.htm

"Battery Disconnect is an easy-to-install system that will allow RV owners to disconnect coach and chassis batteries with just the touch of a switch. With Battery Disconnect, the owner can be sure the batteries are disconnected when his RV is not in use or being stored off-season. It is conveniently located inside the RV, and it's all remote.

The heart of the Battery Disconnect system is another Intellitec invention. A latching relay, capable of carrying heavy coach currents, draws power only when switched on or off; yet, it requires no power to stay open or closed. This sturdy relay is sealed against the environment and is designed for the toughest use."

Currently, I have a simple knife-blade type house battery disconnect. Manual operation - on is on, off is off.

[skcyclist]

Great information Markpolo. I had just found the same item and information on line. Will most likely do the upgrade.

Originally Posted by markopolo

Typical camper vans will have an Isolator or Separator that keeps the chassis and house battery separate but allows both to be charged by the vehicles alternator.

Additionally, there is the house 12v system disconnect which is what I think you are referring to.

Intellitec battery disconnects require no power to stay open or closed. So maybe an upgrade is needed.
http://intellitec.com/pdfs/BATTERY_web/bd.htm

Currently, I have a simple knife-blade type house battery disconnect. Manual operation - on is on, off is off.

[skcyclist]

I tried the Intellitec and it didn't work as advertised. (Well, maybe it does, I just read the operating manual the way I wanted it to read.) The solenoid heated up whether the main was on or off. It was worse than the original. (I need to try again..may not have wired it correctly) I e mailed the vendor and he wrote back the following (which made no sense... but now it does). I may play around with it later. Now it's later and preliminary experiment indicate reversing the polarity momentarily does seem to work. However this will require different wiring and switch(es) than existing set up. May explore this further I retract what I wrote above. The Intellitec may be OK with the proper wiring and switches.

Install the new relay back in the coach. Do not connect the 2 small center
terminals (S & I) just the wires to the big terminals.

Then take 2 jumper wires, 1 hooked to (12v +) & the other hooked to (12v -).

At the same time touch the 2 jumper wires to the small terminals for a
second (momentarily) & let off.

If you touch the (12V +) to the "I" terminal & (12v -) to the "S" terminal
for a second (momentarily) the relay should engage & stay engaged (Power on
inside the coach).

If you touch the (12V +) to the "S" terminal & (12v -) to the "I" terminal
for a second (momentarily) the relay should disengage & stay disengaged
(Power off to the inside of the coach)

When it's engaged you do NOT need any power going to the "S" & "I" terminals
as the relay latches into place & it will not unlatch until you tell it to.

[skcyclist]

I've been wondering why there is a need for this solenoid at all. It appears to simply act as a switch. Marko uses a knife blade switch; simple enough. Why not run appropriate sized wires to appropriate sized main swich on the panel for off and on in lieu of knife blade switch? The solenoid is almost too hot to touch when it's on... a useless drain of power.

Originally Posted by skcyclist

Great information Markpolo. I had just found the same item and information on line. Will most likely do the upgrade.

[Malysoun]

It depends on how it's configured. You're right in that it does act just like a regular switch.
If it's bridging both batteries taking the place of an isolator like how I'm planning on installing one, I don't want to have to switch it on/off every time I start/stop the van.
This is actually one of the more common uses of relays instead of isolators, and yes a non-latching relay will probably heat up pretty good, one model I saw dissipates about 12-watts in normal operation.

In theory, since the Intellitec latches, you shouldn't need to provide continuous power to it, just a brief pulse when you want the circuit closed or opened back up, and it shouldn't be consuming power itself while latched.

You can't wire directly to something that's Ignition accessory switched as that doesn't shut off on it's own.
Likewise any switch that isn't a momentary on will keep feeding power to the relay.
If you want to have manual control of the relay you probably need a double-pole/double-throw momentary toggle with your center pins going to the I/S terminals using top of one side and bottom of the other for ground and making the other two your hot leads.

The way this works with the dual polarity boils down to how the mechanical latch inside operates.
It uses the magnetic north/south of the coil to attract/repel a magnetized rod that wedges against the contact plate preventing the return spring from opening the circuit.

I've been looking at some circuit designs that should handle the momentary and polarity aspects of the problem making it more automated.
I'll update this if the system ends up working the way I expect it to.

Originally Posted by skcyclist

I've been wondering why there is a need for this solenoid at all. It appears to simply act as a switch. Marko uses a knife blade switch; simple enough. Why not run appropriate sized wires to appropriate sized main swich on the panel for off and on in lieu of knife blade switch? The solenoid is almost too hot to touch when it's on... a useless drain of power.

[skcyclist]

I installed the Intellitec + a DPDT momentary switch and it works great. No more current drain.

Originally Posted by Malysoun

It depends on how it's configured. You're right in that it does act just like a regular switch.
If it's bridging both batteries taking the place of an isolator like how I'm planning on installing one, I don't want to have to switch it on/off every time I start/stop the van.
This is actually one of the more common uses of relays instead of isolators, and yes a non-latching relay will probably heat up pretty good, one model I saw dissipates about 12-watts in normal operation.

In theory, since the Intellitec latches, you shouldn't need to provide continuous power to it, just a brief pulse when you want the circuit closed or opened back up, and it shouldn't be consuming power itself while latched.

You can't wire directly to something that's Ignition accessory switched as that doesn't shut off on it's own.
Likewise any switch that isn't a momentary on will keep feeding power to the relay.
If you want to have manual control of the relay you probably need a double-pole/double-throw momentary toggle with your center pins going to the I/S terminals using top of one side and bottom of the other for ground and making the other two your hot leads.

The way this works with the dual polarity boils down to how the mechanical latch inside operates.
It uses the magnetic north/south of the coil to attract/repel a magnetized rod that wedges against the contact plate preventing the return spring from opening the circuit.

I've been looking at some circuit designs that should handle the momentary and polarity aspects of the problem making it more automated.
I'll update this if the system ends up working the way I expect it to.

[Malysoun]

Glad to hear that it's working ok.

I haven't tested this circuit yet, but this is the third or fourth iteration of what I was looking at doing.



The basic theory here, is that when the accessory or override switches are thrown, the coil on the DPDT relay is energized which closes the circuit on the intellitec causing it to engage as well.
Current flows through the coil on the DPDT and through the transistor until the capacitors saturate becoming an impedance which causes current to flow through the potentiometer instead to transistor base which acts like a gate cutting off the flow through the DPDT coil. (Momentary timeout circuit).
The default position of the DPDT is such that if current were present, the intellitec would dis-engage (safety first), however there won't be current to switch the intellitec off until the accessory/override are opened.
It's at this time that the op-amp circuit which is being used as a voltage comparator sees voltage on pin 2 drop to 0vdc, pin 3 can still draw from our previously saturated capacitors until they discharge and the difference between the two voltages causes a signal to be sent engaging the SPDT switch.
The SPDT is connected to continuous power which provides the charge to unlatch the intellitec until the capacitors discharge and the SPDT opens back up.

I should be able to adjust the timeout delay for the first part of the circuit with the potentiometer, I'm still looking into modifying this so that I can adjust the delay on the unlatch pulse.
My other thoughts are that the resistors prior to the SPDT may not be needed as that coil has a 400-Ohm resistance itself. I need to make sure that the signal voltage off pin 1 is enough to close that relay but not keep it open for a long period of time, thus this might be a good place for another potentiometer.

[skcyclist]

So, my RV house battery hasn't been charging by coach motor as supposed to be (I think). Much research and tinkering to find out why, or if it's even supposed to. I found a very helpful post online written by whom? ME, FFS!

Here it all is:
"I solved the house battery not charging problem. There was blown 60 amp fuse in the Ford fuse box under the hood that supplied the aux. battery. While trouble shooting I found a solenoid just above the main electrical box that gets almost too hot to touch when the main switch is on. The main switch must be on to power camper 12V accessories. Also must be on to charge the battery when the vehicle motor is running. Some research suggests hot continuous service solenoids are normal to keep contacts closed (or open?) while they draw 12 watts of power. Somehow this seems like an unnecessary drain on the battery. Anyone know anything about this? e mail me skc@cox.net Steve
Just looked at some alternative wiring set ups. One showed a solenoid that would go on and off with the ignition. That makes a lot more sense than having it on all the time. But maybe I'm overlooking something."

FOCK, I forgot completely about this. Probably just that 60 amp fuse blown again.

Do you know how weird it is to read something you wrote and not remember or recognize it? I don't think I'll forget this again if I by chance live another 10 years (88 by then).

Still, it's nice to help yourself 10 years later.

Originally Posted by skcyclist

I solved the house battery not charging problem. There was blown 60 amp fuse in the Ford fuse box under the hood that supplied the aux. battery. While trouble shooting I found a solenoid just above the main electrical box that gets almost too hot to touch when the main switch is on. The main switch must be on to power camper 12V accessories. Also must be on to charge the battery when the vehicle motor is running. Some research suggests hot continuous service solenoids are normal to keep contacts closed (or open?) while they draw 12 watts of power. Somehow this seems like an unnecessary drain on the battery. Anyone know anything about this? e mail me skc@cox.net Steve

Just looked at some alternative wiring set ups. One showed a solenoid that would go on and off with the ignition. That makes a lot more sense than having it on all the time. But maybe I'm overlooking something.

[Urlauber]

Wow, quite a story, and something to keep in mind for me, being at the beginning of my RV adventures, as well. Sometimes... it's just a fuse!

[skcyclist]

Well, I just checked and the 60-amp fuse for Aux battery is good, so it's not that. Also searched briefly for info on the aux battery and couldn't find much information. The owner's manual doesn't provide much information either. Now I'm wondering if the aux battery ever did charge through the alternator. The Coachmen manual says it does, but the Ford manual isn't specific. Online folks seem confused too. Some say yes others no. It will charge connected to shore power and when the generator runs. I said below I solved the not charging problem but I don't recall ever verifying this. I simply changed the fuse and assumed all was well. The house battery died every couple of years. It may have been kept alive by my periodic generator running and solar panels I installed. I'm totally gaslighted.

Originally Posted by skcyclist

So, my RV house battery hasn't been charging by coach motor as supposed to be (I think). Much research and tinkering to find out why, or if it's even supposed to. I found a very helpful post online written by whom? ME, FFS!

Here it all is:
"I solved the house battery not charging problem. There was blown 60 amp fuse in the Ford fuse box under the hood that supplied the aux. battery. While trouble shooting I found a solenoid just above the main electrical box that gets almost too hot to touch when the main switch is on. The main switch must be on to power camper 12V accessories. Also must be on to charge the battery when the vehicle motor is running. Some research suggests hot continuous service solenoids are normal to keep contacts closed (or open?) while they draw 12 watts of power. Somehow this seems like an unnecessary drain on the battery. Anyone know anything about this? e mail me skc@cox.net Steve
Just looked at some alternative wiring set ups. One showed a solenoid that would go on and off with the ignition. That makes a lot more sense than having it on all the time. But maybe I'm overlooking something."

FOCK, I forgot completely about this. Probably just that 60 amp fuse blown again.

Do you know how weird it is to read something you wrote and not remember or recognize it? I don't think I'll forget this again if I by chance live another 10 years (88 by then).

Still, it's nice to help yourself 10 years later.